I have always found that it is difficult to photograph with other people on long photography trips (be they with photographers or not). In the past, I have always felt guilty if someone is waiting for me or sitting in the car while I am photographing. And, too often the visual and ideological differences between photographers means that one person is photographing while the other person is not (though that can sometimes be an advantage if it pushes you to see things in new ways). Of course, the waiting is especially bad in the summer or winter (but not so bad if there is a nearby body of water and proper rocks for skipping).
Now, my primary problem with photographing on long trips with other photographers is that I am interested in thoroughly exploring specific places or subjects, which are usually different than their interests. That is not to say that I am opposed to making seemingly-random pictures along the way to wherever we are wandering (I say seemingly-random because while the vision may be consistent, the subject is not), but I don't feel that is as personally worthwhile as a concentrated study of an area or subject. And furthermore, I do, in fact, thoroughly enjoy wandering. I believe it is through the experiences we have while exploring and wandering that we discover what it is that moves us to photograph.